Association of daily physical activity with pulmonary artery pressure in HFpEF and HFmrEF NYHA class III patients: a pilot trial-feasibility and first results

Introduction: Supervised physical exercise has been shown to benefit patients with heart failure with preserved/mildly reduced ejection fraction (HFpEF/HfmrEF) by improving symptoms and diastolic function. This study aimed to investigate the correlation between unsupervised daily physical activity and changes in daily pulmonary artery pressure (PAP) in patients with stable NYHA class III heart failure (HF) and left ventricular ejection fraction (LVEF) of 45% or higher.

Methods: Daily physical activity was monitored over a 3-month period using a Holter-ECG with an accelerometer that calculated an activity-associated, heart rate-derived metabolic equivalent of task (MET) score. PAP was measured using an implanted sensor in 17 patients.

Results: During 3 months of PAP monitoring in parallel with Holter ECG in our HF patients (median age 77 [IQR 72-79.5] years, LVEF 55 [49-56] %, mean cardiac index 1.9 ± 0.3), mean, diastolic, and systolic PAP remained unchanged. Patients engaged in unsupervised daily activity with a mean MET score of 5.0 ± 1.2 and a median daily duration of 41 [13-123] minutes. Intensity of daily activity was associated with a higher diastolic PAP on the following day (R² = 0.017, p = 0.003), particularly in female patients and those with pulmonary hypertension (PH) (female: R² = 0.044, p = 0.002; PH: R² = 0.024, p = 0.004). Patients with longer daily activity durations had lower systolic and mean PAP (p = 0.038 and p = 0.048) and a similar diastolic PAP (p = 0.053) after 3 months.

Conclusions: Tracking changes in daily PAP based on intensity and duration of unsupervised daily activity using implanted sensors and a PocketECG^® is feasible. While daily activity duration was not directly linked to diastolic PAP on the first day after daily activity, intensity, especially in female and PH patients, was associated with increased diastolic PAP. In addition, longer daily activity, rather than higher intensity, might be more important for lowering PAP in the long term. Further research in larger trials is warranted to confirm these findings.